From 271df90e4e530c17f237b27034d6341cb2c2f536 Mon Sep 17 00:00:00 2001 From: Vitaly Wool Date: Thu, 16 Mar 2017 16:40:19 -0700 Subject: [PATCH 1/6] z3fold: fix spinlock unlocking in page reclaim Commmit 5a27aa822029 ("z3fold: add kref refcounting") introduced a bug in z3fold_reclaim_page() with function exit that may leave pool->lock spinlock held. Here comes the trivial fix. Fixes: 5a27aa822029 ("z3fold: add kref refcounting") Link: http://lkml.kernel.org/r/20170311222239.7b83d8e7ef1914e05497649f@gmail.com Reported-by: Alexey Khoroshilov Signed-off-by: Vitaly Wool Cc: Dan Streetman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/z3fold.c | 1 + 1 file changed, 1 insertion(+) diff --git a/mm/z3fold.c b/mm/z3fold.c index 8970a2fd3b1a..f9492bccfd79 100644 --- a/mm/z3fold.c +++ b/mm/z3fold.c @@ -667,6 +667,7 @@ static int z3fold_reclaim_page(struct z3fold_pool *pool, unsigned int retries) z3fold_page_unlock(zhdr); spin_lock(&pool->lock); if (kref_put(&zhdr->refcount, release_z3fold_page)) { + spin_unlock(&pool->lock); atomic64_dec(&pool->pages_nr); return 0; } From 5be9b730b09c45c358bbfe7f51d254e306cccc07 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Thu, 16 Mar 2017 16:40:21 -0700 Subject: [PATCH 2/6] kasan: add a prototype of task_struct to avoid warning Add a prototype of task_struct to fix below warning on arm64. In file included from arch/arm64/kernel/probes/kprobes.c:19:0: include/linux/kasan.h:81:132: error: 'struct task_struct' declared inside parameter list will not be visible outside of this definition or declaration [-Werror] static inline void kasan_unpoison_task_stack(struct task_struct *task) {} As same as other types (kmem_cache, page, and vm_struct) this adds a prototype of task_struct data structure on top of kasan.h. [arnd] A related warning was fixed before, but now appears in a different line in the same file in v4.11-rc2. The patch from Masami Hiramatsu still seems appropriate, so let's take his version. Fixes: 71af2ed5eeea ("kasan, sched/headers: Remove from ") Link: https://patchwork.kernel.org/patch/9569839/ Link: http://lkml.kernel.org/r/20170313141517.3397802-1-arnd@arndb.de Signed-off-by: Arnd Bergmann Signed-off-by: Masami Hiramatsu Acked-by: Alexander Potapenko Acked-by: Andrey Ryabinin Cc: Dmitry Vyukov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/kasan.h | 1 + 1 file changed, 1 insertion(+) diff --git a/include/linux/kasan.h b/include/linux/kasan.h index 1c823bef4c15..5734480c9590 100644 --- a/include/linux/kasan.h +++ b/include/linux/kasan.h @@ -6,6 +6,7 @@ struct kmem_cache; struct page; struct vm_struct; +struct task_struct; #ifdef CONFIG_KASAN From d0f33ac9ae7b2a727fb678235ae37baf1d0608d5 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Thu, 16 Mar 2017 16:40:24 -0700 Subject: [PATCH 3/6] mm, x86: fix native_pud_clear build error We still get a build error in random configurations, after this has been modified a few times: In file included from include/linux/mm.h:68:0, from include/linux/suspend.h:8, from arch/x86/kernel/asm-offsets.c:12: arch/x86/include/asm/pgtable.h:66:26: error: redefinition of 'native_pud_clear' #define pud_clear(pud) native_pud_clear(pud) My interpretation is that the build error comes from a typo in __PAGETABLE_PUD_FOLDED, so fix that typo now, and remove the incorrect #ifdef around the native_pud_clear definition. Fixes: 3e761a42e19c ("mm, x86: fix HIGHMEM64 && PARAVIRT build config for native_pud_clear()") Fixes: a00cc7d9dd93 ("mm, x86: add support for PUD-sized transparent hugepages") Link: http://lkml.kernel.org/r/20170314121330.182155-1-arnd@arndb.de Signed-off-by: Arnd Bergmann Ackedy-by: Dave Jiang Cc: Matthew Wilcox Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: Thomas Garnier Cc: Kees Cook Cc: Dave Hansen Cc: Hugh Dickins Cc: Borislav Petkov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/x86/include/asm/pgtable-3level.h | 3 --- arch/x86/include/asm/pgtable.h | 2 +- 2 files changed, 1 insertion(+), 4 deletions(-) diff --git a/arch/x86/include/asm/pgtable-3level.h b/arch/x86/include/asm/pgtable-3level.h index 72277b1028a5..50d35e3185f5 100644 --- a/arch/x86/include/asm/pgtable-3level.h +++ b/arch/x86/include/asm/pgtable-3level.h @@ -121,12 +121,9 @@ static inline void native_pmd_clear(pmd_t *pmd) *(tmp + 1) = 0; } -#if !defined(CONFIG_SMP) || (defined(CONFIG_HIGHMEM64G) && \ - defined(CONFIG_PARAVIRT)) static inline void native_pud_clear(pud_t *pudp) { } -#endif static inline void pud_clear(pud_t *pudp) { diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h index 1cfb36b8c024..585ee0d42d18 100644 --- a/arch/x86/include/asm/pgtable.h +++ b/arch/x86/include/asm/pgtable.h @@ -62,7 +62,7 @@ extern struct mm_struct *pgd_page_get_mm(struct page *page); # define set_pud(pudp, pud) native_set_pud(pudp, pud) #endif -#ifndef __PAGETABLE_PMD_FOLDED +#ifndef __PAGETABLE_PUD_FOLDED #define pud_clear(pud) native_pud_clear(pud) #endif From 171012f561274784160f666f8398af8b42216e1f Mon Sep 17 00:00:00 2001 From: Dmitry Vyukov Date: Thu, 16 Mar 2017 16:40:27 -0700 Subject: [PATCH 4/6] mm: don't warn when vmalloc() fails due to a fatal signal When vmalloc() fails it prints a very lengthy message with all the details about memory consumption assuming that it happened due to OOM. However, vmalloc() can also fail due to fatal signal pending. In such case the message is quite confusing because it suggests that it is OOM but the numbers suggest otherwise. The messages can also pollute console considerably. Don't warn when vmalloc() fails due to fatal signal pending. Link: http://lkml.kernel.org/r/20170313114425.72724-1-dvyukov@google.com Signed-off-by: Dmitry Vyukov Reviewed-by: Matthew Wilcox Acked-by: Kirill A. Shutemov Acked-by: Michal Hocko Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/vmalloc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 0dd80222b20b..0b057628a7ba 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -1683,7 +1683,7 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask, if (fatal_signal_pending(current)) { area->nr_pages = i; - goto fail; + goto fail_no_warn; } if (node == NUMA_NO_NODE) @@ -1709,6 +1709,7 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask, warn_alloc(gfp_mask, NULL, "vmalloc: allocation failure, allocated %ld of %ld bytes", (area->nr_pages*PAGE_SIZE), area->size); +fail_no_warn: vfree(area->addr); return NULL; } From 55adc1d05dca9e949cdf46c747cb1e91c0e9143d Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Thu, 16 Mar 2017 16:40:30 -0700 Subject: [PATCH 5/6] mm: add private lock to serialize memory hotplug operations Commit bfc8c90139eb ("mem-hotplug: implement get/put_online_mems") introduced new functions get/put_online_mems() and mem_hotplug_begin/end() in order to allow similar semantics for memory hotplug like for cpu hotplug. The corresponding functions for cpu hotplug are get/put_online_cpus() and cpu_hotplug_begin/done() for cpu hotplug. The commit however missed to introduce functions that would serialize memory hotplug operations like they are done for cpu hotplug with cpu_maps_update_begin/done(). This basically leaves mem_hotplug.active_writer unprotected and allows concurrent writers to modify it, which may lead to problems as outlined by commit f931ab479dd2 ("mm: fix devm_memremap_pages crash, use mem_hotplug_{begin, done}"). That commit was extended again with commit b5d24fda9c3d ("mm, devm_memremap_pages: hold device_hotplug lock over mem_hotplug_{begin, done}") which serializes memory hotplug operations for some call sites by using the device_hotplug lock. In addition with commit 3fc21924100b ("mm: validate device_hotplug is held for memory hotplug") a sanity check was added to mem_hotplug_begin() to verify that the device_hotplug lock is held. This in turn triggers the following warning on s390: WARNING: CPU: 6 PID: 1 at drivers/base/core.c:643 assert_held_device_hotplug+0x4a/0x58 Call Trace: assert_held_device_hotplug+0x40/0x58) mem_hotplug_begin+0x34/0xc8 add_memory_resource+0x7e/0x1f8 add_memory+0xda/0x130 add_memory_merged+0x15c/0x178 sclp_detect_standby_memory+0x2ae/0x2f8 do_one_initcall+0xa2/0x150 kernel_init_freeable+0x228/0x2d8 kernel_init+0x2a/0x140 kernel_thread_starter+0x6/0xc One possible fix would be to add more lock_device_hotplug() and unlock_device_hotplug() calls around each call site of mem_hotplug_begin/end(). But that would give the device_hotplug lock additional semantics it better should not have (serialize memory hotplug operations). Instead add a new memory_add_remove_lock which has the similar semantics like cpu_add_remove_lock for cpu hotplug. To keep things hopefully a bit easier the lock will be locked and unlocked within the mem_hotplug_begin/end() functions. Link: http://lkml.kernel.org/r/20170314125226.16779-2-heiko.carstens@de.ibm.com Signed-off-by: Heiko Carstens Reported-by: Sebastian Ott Acked-by: Dan Williams Acked-by: Rafael J. Wysocki Cc: Michal Hocko Cc: Vladimir Davydov Cc: Ben Hutchings Cc: Gerald Schaefer Cc: Martin Schwidefsky Cc: Greg Kroah-Hartman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/memremap.c | 4 ---- mm/memory_hotplug.c | 6 +++++- 2 files changed, 5 insertions(+), 5 deletions(-) diff --git a/kernel/memremap.c b/kernel/memremap.c index 06123234f118..07e85e5229da 100644 --- a/kernel/memremap.c +++ b/kernel/memremap.c @@ -247,11 +247,9 @@ static void devm_memremap_pages_release(struct device *dev, void *data) align_start = res->start & ~(SECTION_SIZE - 1); align_size = ALIGN(resource_size(res), SECTION_SIZE); - lock_device_hotplug(); mem_hotplug_begin(); arch_remove_memory(align_start, align_size); mem_hotplug_done(); - unlock_device_hotplug(); untrack_pfn(NULL, PHYS_PFN(align_start), align_size); pgmap_radix_release(res); @@ -364,11 +362,9 @@ void *devm_memremap_pages(struct device *dev, struct resource *res, if (error) goto err_pfn_remap; - lock_device_hotplug(); mem_hotplug_begin(); error = arch_add_memory(nid, align_start, align_size, true); mem_hotplug_done(); - unlock_device_hotplug(); if (error) goto err_add_memory; diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 295479b792ec..6fa7208bcd56 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -125,9 +125,12 @@ void put_online_mems(void) } +/* Serializes write accesses to mem_hotplug.active_writer. */ +static DEFINE_MUTEX(memory_add_remove_lock); + void mem_hotplug_begin(void) { - assert_held_device_hotplug(); + mutex_lock(&memory_add_remove_lock); mem_hotplug.active_writer = current; @@ -147,6 +150,7 @@ void mem_hotplug_done(void) mem_hotplug.active_writer = NULL; mutex_unlock(&mem_hotplug.lock); memhp_lock_release(); + mutex_unlock(&memory_add_remove_lock); } /* add this memory to iomem resource */ From 15c9e10d9ad4d41d076148bbff1de7f659f68852 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Thu, 16 Mar 2017 16:40:33 -0700 Subject: [PATCH 6/6] drivers core: remove assert_held_device_hotplug() The last caller of assert_held_device_hotplug() is gone, so remove it again. Link: http://lkml.kernel.org/r/20170314125226.16779-3-heiko.carstens@de.ibm.com Signed-off-by: Heiko Carstens Acked-by: Dan Williams Cc: Michal Hocko Cc: "Rafael J. Wysocki" Cc: Vladimir Davydov Cc: Ben Hutchings Cc: Gerald Schaefer Cc: Martin Schwidefsky Cc: Sebastian Ott Cc: Greg Kroah-Hartman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/base/core.c | 5 ----- include/linux/device.h | 1 - 2 files changed, 6 deletions(-) diff --git a/drivers/base/core.c b/drivers/base/core.c index 684bda4d14a1..6bb60fb6a30b 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -639,11 +639,6 @@ int lock_device_hotplug_sysfs(void) return restart_syscall(); } -void assert_held_device_hotplug(void) -{ - lockdep_assert_held(&device_hotplug_lock); -} - #ifdef CONFIG_BLOCK static inline int device_is_not_partition(struct device *dev) { diff --git a/include/linux/device.h b/include/linux/device.h index 30c4570e928d..9ef518af5515 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -1140,7 +1140,6 @@ static inline bool device_supports_offline(struct device *dev) extern void lock_device_hotplug(void); extern void unlock_device_hotplug(void); extern int lock_device_hotplug_sysfs(void); -void assert_held_device_hotplug(void); extern int device_offline(struct device *dev); extern int device_online(struct device *dev); extern void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode);